### What changes were proposed in this pull request?
Currently, inferring nested structs is always using `MapType`.
This behavior causes an issue because it infers the schema with a value type of the first field of the struct as below:
```python
data = [{"inside_struct": {"payment": 100.5, "name": "Lee"}}]
df = spark.createDataFrame(data)
df.show(truncate=False)
+--------------------------------+
|inside_struct |
+--------------------------------+
|{name -> null, payment -> 100.5}|
+--------------------------------+
```
The "name" became `null`, but it should've been `"Lee"`.
In this case, we need to be able to infer the schema with a `StructType` instead of a `MapType`.
Therefore, this PR proposes adding an new configuration `spark.sql.pyspark.inferNestedDictAsStruct.enabled` to handle which type is used for inferring nested structs.
- When `spark.sql.pyspark.inferNestedDictAsStruct.enabled` is `false` (by default), inferring nested structs by `MapType`
- When `spark.sql.pyspark.inferNestedDictAsStruct.enabled` is `true`, inferring nested structs by `StructType`
### Why are the changes needed?
Because always inferring the nested structs by `MapType` doesn't work properly for some cases.
### Does this PR introduce _any_ user-facing change?
New configuration `spark.sql.pyspark.inferNestedDictAsStruct.enabled` is added.
### How was this patch tested?
Added an unit test
Closes#33214 from itholic/SPARK-35929.
Lead-authored-by: itholic <haejoon.lee@databricks.com>
Co-authored-by: Hyukjin Kwon <gurwls223@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
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